Athletic Bilbao coach Marcelo Bielsa says he is not worried about his job security as his struggling side prepare for Friday's highly-charged Basque derby against the impressive Real Sociedad.

Athletic come into the game in 15th position, with just one point from their last three games, and having been beaten 4-0 by Espanyol in their last home game. Sociedad, on the other hand, are sixth in the Primera Division table, with three wins and three draws in their last six games.

Friday evening is also likely to have added emotion in Bilbao, as it is the last derby at the city's historic San Mames stadium, which is being knocked down this summer. Bielsa said that whatever happened in the game he was not worried about his job.

"They will not sack me because they have patience," Bielsa said. "I believe patience is a characteristic which the Basques have. This game is of vital importance, but it would be whoever the opponent was, given the need to turn things around."

The derby will be 'El Loco's' 100th game in charge of Athletic, his longest ever spell at any one club. Asked to evaluate his time in charge, which has brought the highs of a run to last season's Europa League final past Manchester United, Paris Saint Germain and Schalke, but also the lows of two cup final defeats and this season's struggles in the bottom half of the table, Bielsa admitted he had not done well.

"My evaluation of the 100 games would have to be a negative one," he said. "Last year we were tenth in La Liga when we could have been fifth, and now we are in the bottom third of the table, when we could be higher. The management of the human material which the club put in my hands has not been good enough."

The mood along the Basque coast in San Sebastian is much better ahead of the game, with Philippe Montainer's young side having their best season in a decade. Sociedad's French attacker Antoine Griezmann told Thursday's Mundo Deportivo that everyone around the club was looking forward to taking on Athletic.

"This is not just another game, this is a derby," Griezmann said. "It is such an important game for us, for the club and for the fans. Everyone is hanging on what you do, you must be at your best and give everything for the 90 minutes. When you arrive here, people only talk about Athletic in the youth ranks. The most important thing is to beat them. And the same now. It is a nice game and I hope we can do something. It must be incredible to win there.

"They are at home, but we are confident and feeling good. We are playing good football and on a good run. We have just lost one game in the last few months, we have picked up a lot of points and we want to keep doing that."